U.S. Pat. Nos. 4,057,159, 4,059,198 and 4,485,932 disclose child-resistant closure and container prescription packages that include a container or vial, a closure, and a spring/seal disk arrangement disposed between the closure and the container. The closure has lugs on an inside surface of a skirt that cooperate with external locking notches or pockets on projections around the mouth of the container for securing the closure to the container. An internal abutment on the closure cooperates with the spring/seal disk(s) to urge the closure away from the container so that the lugs are resiliently captured within the notches. When it is desired to remove the closure, the closure is pushed toward the container so that the lugs clear the notches, and then turned counterclockwise. When the closure is assembled to the container, the lugs cam beneath surfaces on the projections against the force of the spring seal disk(s) until the lugs snap into the notches on the projections.
Although the closure and container packages disclosed in the noted patents have enjoyed substantial commercial acceptance and success, improvements remain desirable. For example, it can be difficult for adults with impaired dexterity to push and twist the closure with respect to the container to open the package for access to the contents. One general object of the present invention to provide a closure and container package, a closure and a container for use in such a package, and/or a method of making such a package, in which the closure can be secured to the container in a child-resistant mode of operation as described above, and in a non-child-resistant mode of operation for use by adults with impaired manual dexterity, for example, when child-resistance is not needed. It is another and more specific object of the present invention to provide a package, a container, a closure and/or a method of the described character that achieves the non-child-resistant mode of operation with little additional material, tooling or labor cost as compared with conventional child-resistant packages as described in the noted patents.
Another general object of the present invention is to provide a two-piece package of the subject type—i.e., a closure and a container without a separate spring element—in which the spring forces for holding the closure on the container are provided by resilient flexure of either or both of the closure and the container. In furtherance of this objective, another object of the invention is to provide a package in which the closure and container are economical to manufacture. A further objective is to provide a package that is readily suited to automated packaging—i.e., is automation friendly.
The present invention embodies a number of aspects that can be implemented separately from or, more preferably, in combination with each other.
A child-resistant package in accordance with a first aspect of the present invention includes a container having a wall surrounding an open mouth, a plurality of external projections extending radially outwardly from the container wall at positions spaced from the mouth, notches on undersides of the projections, and an external surface on the container wall that slopes radially inwardly and axially upwardly between the projections and the mouth. A closure has an annular base wall with an internal peripheral edge, an external a peripheral skirt and a plurality of internal lugs on the skirt. The internal peripheral edge of the base wall is engagable with the sloping external wall surface of the container between the projections and the mouth for both sealing the package and resiliently urging the closure lugs into the notches of the projections. The holding forces can be supplied by resilient flexure of the closure or the container, or both. A two-piece package in accordance with this aspect of the invention thus eliminates any need for additional spring/seal disk elements in the assembly.
A package in accordance with another aspect of the present invention has both child-resistant and non-child-resistant modes of operation. A container has an end with an open mouth surrounded by a container wall with a central axis and at least one first lock element extending radially outwardly from the wall. A closure includes an annular base wall having inner and outer peripheral edges. A cylindrical skirt extends from the outer peripheral edge of the base wall, and at least one second lock element is disposed on the skirt. A projection extends axially from the inner peripheral edge of the base wall in a direction opposite from the skirt. The projection has an annular sidewall spaced radially inwardly from the outer peripheral edge of the skirt. The closure is adapted to be secured to the container in a child-resistant mode of operation with the at least one second lock element on the skirt releasably engaged with the at least one first lock element on the container wall, and with the inner peripheral edge of the base wall in resilient engagement with the outer surface of the container wall to bias the lock elements in engagement with each other and to seal the package. The closure is adapted to be inverted and secured to the container in a non-child-resistant mode of operation with the annular sidewall of the dome received in plug-sealing engagement within the container mouth.
In the preferred embodiments of the invention, the annular base wall of the closure is flat and lies in a plane between the inner and outer peripheral edges of the base wall. The inner and outer peripheral edges of the base wall preferably are circular and concentric. In some embodiments of the invention, the portion of the container wall between the lock element(s) on the container wall and the container mouth tapers in radial thickness. This container wall portion is flexible radially inwardly upon engagement with the inner peripheral edge of the base wall in the child-resistant mode of operation, and radially outwardly upon engagement with the closure projection in the non-child-resistant mode of operation. In one embodiment, an undercut on the inner surface of the container enhances the flexibility of the container end. In other embodiments of the invention, an external stiffening bead or rib surrounds the container mouth to prevent flexure of the container wall portion surrounding the mouth, and the closure itself is resiliently flexible radially outwardly in the child-resistant mode of operation for sealing the package and biasing the locking elements in engagement with each other. In some embodiments of the invention, an external bead on the closure projection engages an internal bead on the container wall to secure the closure to the container in the non-child-resistant mode of operation. In other embodiments of the invention, an external wall on the closure surrounds the projection and externally engages the container to secure the closure to the container in the non-child-resistant mode of operation.